1. Fraunhofer Institute for High Frequency Physics and Radar Techniques FHR, Fraunhoferstr. 20, 53343 Wachtberg, Germany
2. ZESS - Center for Sensor Systems, University of Siegen, Paul-Bonatz-Str. 9-11, 57076, Germany
3. Institute of Electronic Circuits, Ruhr-Universität Bochum, Universitätsstr. 150, 44789, Germany
4. Institute of Integrated Circuits, Ruhr-Universität Bochum, Universitätsstr. 150, 44789, Germany